" The fact that all benzodiazepines are lipid soluble to varying degrees means that benzodiazepines and their active metabolites bind to plasma proteins. The extent of this binding is proportional to their lipid solubility. The amount of protein binding varies from 70 to 99 percent. Distribution, onset, and termination of action after a single dose are thus largely determined by benzodiazepine lipid solubility, not elimination "

― , Kaplan & Sadock's Synopsis of Psychiatry: Behavioral Sciences/Clinical Psychiatry